What adjustments can be made to the current regimen of lisinopril (angiotensin-converting enzyme inhibitor) 40mg once daily and amlodipine (calcium channel blocker) 5mg twice daily for a 78-year-old patient with diabetes and uncontrolled hypertension?

Adjusting Antihypertensive Therapy for an Elderly Diabetic Patient with Uncontrolled Hypertension

For a 78-year-old diabetic patient with uncontrolled blood pressure on lisinopril 40mg daily and amlodipine 5mg twice daily, the optimal adjustment would be to add a thiazide diuretic as a third agent while maintaining the current medications. 1, 2

Current Regimen Analysis

The patient is currently on:

• Lisinopril 40mg once daily (ACE inhibitor at maximum dose)
• Amlodipine 5mg twice daily (Calcium channel blocker, total 10mg daily)

Despite this combination, blood pressure remains uncontrolled. This is not surprising as:

• More than 70% of hypertensive patients require at least two antihypertensive agents, and many elderly patients with diabetes need three or more agents 2
• The current regimen includes two appropriate first-line agents (ACE inhibitor and CCB), but may need additional therapy 1
• Elderly diabetic patients often have resistant hypertension requiring multiple medications 3

Recommended Treatment Adjustments

Primary Recommendation:

1. Add a thiazide or thiazide-like diuretic (e.g., chlorthalidone 12.5-25mg daily or hydrochlorothiazide 12.5-25mg daily)
2. Maintain current doses of lisinopril and amlodipine

Rationale:

• The 2024 DCRM guidelines specifically recommend a three-drug combination of ACE inhibitor/ARB + CCB + thiazide diuretic when two drugs are insufficient 1
• This triple combination is supported by multiple guidelines as the most effective approach for resistant hypertension 1, 2
• Adding a thiazide diuretic complements the mechanisms of action of the existing medications 1
• This approach is particularly effective in elderly patients with isolated systolic hypertension 4

Special Considerations for This Patient

Age-Related Factors:

• At 78 years old, this patient requires careful monitoring for orthostatic hypotension when adding a new agent 2
• Start the thiazide diuretic at a low dose (e.g., hydrochlorothiazide 12.5mg) and titrate gradually 2
• Monitor renal function and electrolytes within 2-4 weeks of adding the diuretic 1, 2

Diabetes-Related Factors:

• The target BP for elderly diabetic patients should be <130/80 mmHg, but avoid diastolic BP <60 mmHg 1
• ACE inhibitors are appropriate first-line therapy for diabetic patients (already in place with lisinopril) 1
• Monitor for worsening glycemic control with thiazide diuretics, though this effect is usually minimal at lower doses 2

Alternative Approaches (If Primary Recommendation Fails)

1. Consider switching lisinopril to an ARB if cough or angioedema develops
2. Consider adding a mineralocorticoid receptor antagonist (MRA) like spironolactone 25mg daily if BP remains uncontrolled after adding a thiazide diuretic 1
3. Consider simplifying the regimen to once-daily dosing using combination pills to improve adherence 2

Monitoring Recommendations

• Check blood pressure within 2-4 weeks after adding the thiazide diuretic 2
• Monitor serum potassium, sodium, and renal function within 3-4 weeks 1, 2
• Assess for orthostatic hypotension, especially during the initial weeks of therapy 2
• Once target BP is achieved, follow up every 3-5 months 2

Common Pitfalls to Avoid

• Therapeutic inertia: Failing to add a third agent when two medications are insufficient 2
• Inadequate monitoring: Not checking electrolytes and renal function after adding a diuretic 2
• Excessive BP lowering: Avoid reducing diastolic BP below 60 mmHg in elderly patients 1
• Drug interactions: Be cautious with NSAIDs, which can reduce the effectiveness of all antihypertensive medications 2

This approach aligns with current guidelines and provides the best chance of achieving blood pressure control while minimizing adverse effects in this elderly diabetic patient.